This invention is related to powder coating compositions and in particular, to a thermosetting polymer powder coating composition.
To curb pollution caused by conventional solvent based coating systems, the automobile and truck manufacturing industry intends to utilize powder coating compositions. However, the industry demands that these powder coating compositions be of a high quality.
The following patents are directed to powder coating compositions containing glycidyl methacrylate polymers:
______________________________________ Labana U.S. Pat. No. 3,730,930 Issued May 1, 1973 Labana U.S. Pat. No. 3,752,870 Issued Aug. 14, 1973 Labana et al U.S. Pat. No. 3,770,848 Issued Nov. 6, 1973 Theodore et al U.S. Pat. No. 3,781,379 Issued Dec. 25, 1973 Labana et al U.S. Pat. No. 3,781,380 Issued Dec. 25, 1973 Blackley et al U.S. Pat. No. 3,857,905 Issued Dec. 31, 1974 Matsui et al U.S. Pat. No. 3,876,587 Issued Apr. 8, 1975 Labana et al U.S. Pat. No. 3,880,946 Issued Apr. 29, 1975 Labana et al U.S. Pat. No. 3,880,947 Issued Apr. 29, 1975 ______________________________________
Several of the above powder compositions have poor stability and readily react under normal storage conditions while others use undesirable flow control agents. In general, none of the powder compositions provide an acceptable high quality powder coating composition useful for application to the exterior of automobiles and trucks. There is a need for a storage-stable powder coating composition that forms finishes of excellent appearance and that has good physical properties and that can withstand long periods of weathering.